Evaluation of bedside blood glucose monitoring by the phlebotomy team in an acute general care hospital

A feasibility study was undertaken to evaluate laboratory phlebotomists performing bedside glucose monitoring (BGM) over a 3-month period on a medical and surgical floor. Specific questions included: feasibility of providing testing on a 24-h basis, accuracy, appropriate utilization, effect on patient care, and an analysis of cost. In all, 1975 tests were performed on 114 patients. BGM results were within 15% of the laboratory's result 97% of the time. Patient and physician satisfaction was high. Although the cost of BGM is slightly higher than a laboratory glucose test, its use appeared to reduce the length of hospital stay by 0.47 days. Practical information on initiating a highly successful BGM program is provided.     

Pharmacological properties of Ca2+-activated K+ currents of ramified murine brain macrophages

Using the whole-cell configuration of the patch clamp technique, calcium-activated potassium currents (I_K,Ca) were investigated in ramified murine brain macrophages. In order to induce I_K,Ca the intracellular concentration of nominal free Ca²⁺ was adjusted to 1μM. The Ca²⁺-activated K⁺ current of brain macrophages did not show any voltage dependence at test potentials between –120 and +30mV. A tenfold change in extracellular K⁺ concentration shifted the reversal potential of I_K,Ca by 51mV. The bee venom toxin apamin applied at concentrations of up to 1μM did not affect I_K,Ca. Ca²⁺-activated K⁺ currents of ramified brain macrophages were highly sensitive to extracellularly applied charybdotoxin (CTX). The half-maximal effective concentration of CTX was calculated to be 4.3nM. In contrast to CTX, the scorpion toxin kaliotoxin did not inhibit I_K,Ca at concentrations between 1 and 50nM. Tetraethylammonium (TEA) blocked 8.0% of I_K,Ca at a concentration of 1mM, whereas 31.4% of current was blocked by 10mM TEA. Several inorganic polyvalent cations were tested at a concentration of 2mM for their ability to block I_K,Ca. La³⁺ reduced I_K,Ca by 72.8%, whereas Cd²⁺ decreased I_K,Ca by 17.4%; in contrast, Ni²⁺ did not have any effect on I_K,Ca. Ba²⁺ applied at a concentration of 1mM reduced I_K,Ca voltage-dependently at hyperpolarizing potentials. Received: 17 January / Accepted: 5 May 1997     

Ultrasensitive analysis of the intestinal absorption and compartmentalization of aluminium in uraemic rats: a 26Al tracer study employing accelerator mass spectrometry

BACKGROUND: Developments in accelerator mass spectrometry (AMS) now permit the determination of femtogram amounts of 26Al in blood and in various tissues with good precision and free of external contamination. METHODS: In the present study we used trace quantities of 26Al to investigate the intestinal absorption and compartmentalization of aluminium in rats with renal failure (Nx, 5/6 nephrectomy) and in pair- fed controls (C). Single oral doses of 20 ng 26Al were administered to six animals in each group and, subsequently, 24-h post-load 26Al was analysed in serum, urine, bone, liver, and spleen by means of AMS. RESULTS: Serum concentrations of 26Al were significantly lower in uraemic rats compared to controls, whereas urinary excretion was comparable (Nx, 7.11 +/- 5.78 pg/day vs C, 9.46 +/- 6.10 pg/day), suggesting a higher fraction of ultrafiltrable serum 26Al in uraemia. The target tissues of cellular transferrin-mediated 26Al uptake, liver and spleen, tended to show a larger degree of aluminium accumulation in controls (0.26 +/- 0.31 pg/g vs Nx, 0.14 +/- 0.10 pg/g and 0.37 +/- 0.27 pg/g vs Nx, 0.25 +/- 0.27 pg/g respectively). In contrast, in bone, a site of extracellular aluminium deposition, 26Al concentrations were more elevated in uraemia (1.22 +/- 0.59 pg/g vs C: 0.68 +/- 0.30 pg/g). Estimated total 26Al accumulation in all measured target tissues was significantly higher in uraemic rats (28.15 +/- 9.90 pg vs C: 17.03 +/- 7.03 pg) and total recovery of 26Al from tissue and urine was 26.58 +/- 6.74 pg in controls and 35.75 +/- 7.03 pg in uraemic animals, suggesting a fractional absorption of 0.133% and 0.175% respectively. CONCLUSIONS: Our data suggest that fractional absorption from a dietary level dose of 26Al is about 0.13%. Compartmentalization occurs in transferrin-dependent target tissues such as liver and spleen; however, in quantitative terms extracellular deposition in bone is more important. Uraemia has a significant effect on the intestinal absorption and compartmentalization of aluminium. It enhances fractional absorption and increases subsequent extracellular deposition of aluminium in bone. However, at the same time uraemia does not increase transferrin-dependent cellular accumulation of aluminium in liver and spleen.      

Effects of recombinant human erythropoietin (rhEPO) on myelo-and thrombopoiesis of rabbits

The effects of recombinant human erythropoietin (rhEPO, Recormon^R, CAS 122312-54-3) on the differential leucocyte counts and platelets of rabbits were investigated after the repeated application of a single dose of rhEPO. Therefore, 150 IU rhEPO (n = 5), 300 IU rhEPO (n = 6), or 600 IU rhEPO (n = 5) per animal was injected once on three separate occasions with an interval of 5–6 weeks between each injection. Six animals were used to study the potential effect of the solvent alone.rhEPO showed a significant time effect on the differential leucocyte counts and platelets of rabbits. The decrease in total white blood cells count (WBC) on the third, fourth and sixth day after rhEPO administration was due to a decrease in lymphocytes. These results support the hypothesis that the enhanced demand of one cell line leads to a down-modulation of the production of other cell line(s).     

Proprioceptive evoked potentials in man: cerebral responses to changing weight loads on the hand

The retrotrapezoid nucleus (RTN), a part of the rostral ventrolateral medulla, is involved in the control of breathing. The mechanisms by which the RTN modulate the activity of respiratory neurons during chemoreceptor stimulation are not fully understood. This electrophysiological study performed in the cat demonstrates that 18 out of 22 RTN neurons receive inputs from the commissural subnucleus of the solitary tract (cNTS), the peripheral chemoreceptor afferents projection site. Moreover, six RTN neurons are found to present interconnection between RTN and the ventrolateral subnucleus of the solitary tract, an area containing mainly bulbo-spinal respiratory neurons. The present data suggest that RTN play a key role by concomitantly integrating chemosensitive informations relayed by the cNTS and providing an influence on the respiratory network.     

Basic fibroblast growth factor synthesis by human peritoneal mesothelial cells: induction by interleukin-1

Peritoneal mesothelial cells are uniquely located to regulate cellular events in the peritoneal cavity and are an important source for various cytokines and growth factors. This study was conducted to analyze the capacity of human peritoneal mesothelial cells (HPMCs) to synthesize and release basic fibroblast growth factor (bFGF) and to characterize its regulation by inflammatory cytokines. HPMCs constitutively synthesized and released considerable amounts of bFGF as detected by a specific immunoassay. Almost 80% of bFGF (1547 +/- 173 pg/10(5) cells) was localized intracellularly. Approximately 20% of the bFGF (357 +/- 27 pg/10(5) cells) was associated with extracellular matrix components on the HPMC surface. Small amounts of bFGF (<1%) were detectable in tissue culture supernatants (8.4 +/- 1.4 pg/10(5) cells). Treatment of HPMCs with interleukin-1beta (IL-1beta; 1 ng/ml) resulted in a significant increase in bFGF production. The intracellular bFGF content showed a rapid but only transient increase, which was significant above background levels after 24 hours (41% increase; P < 0.05). This increase in intracellular bFGF concentration was associated with an induction of the release of bFGF. Within 96 hours, the release of bFGF to the cell surface and into the supernatant increased by 58% (564 +/- 52.4 pg/10(5) cells; P < 0.01) and by 214% (26.4 +/- 3.2 pg/10(5) cells; P < 0.001), respectively. Neither tumor necrosis factor-alpha nor interferon-gamma affected bFGF synthesis by HPMCs. Stimulation of HPMCs with IL-1beta increased steady-state levels of bFGF-specific mRNA. Immunohistochemical analyses of peritoneal tissue revealed constitutive expression of bFGF by HPMCs. This in situ expression proved to be most pronounced in areas of serosal inflammation in activated HPMCs. Our study demonstrates that HPMCs synthesize and release significant amounts of bFGF and that the expression of this growth factor is significantly up-regulated by the proinflammatory cytokine IL-1beta. The data support the view that HPMCs are key regulators of abdominal disease processes such as peritonitis, peritoneal fibrosis, or peritoneal tumor metastasis.     

Human chromosome 16 conservation in primates

A study was made of the organization of the chromosome orthologous to HSA16 in primates using a panel of 8 BAC probes spanning human chromosome 16. The probes were used in FISH experiments on great apes and on representatives of the Old World monkeys, New World monkeys, and lemurs. The domestic cat was used as an outgroup. The results indicate that 16p and 16q were separate chromosomes in a primate ancestor. They fused in a Catarrhini ancestor giving rise to the present day form found in HSA, great apes, and Old World monkeys. Several rearrangements were found in New World monkeys.     

Microbial exposure of rural school children, as assessed by levels of N-acetyl-muramic acid in mattress dust, and its association with respiratory health

BACKGROUND: Endotoxin exposure has been shown to be associated with a decreased prevalence of atopic sensitization and symptoms. Yet endotoxin represents only a part of the indoor microbial exposure. Muramic acid, a constituent of peptidoglycan, is present in gram-negative and gram-positive bacteria in the environment and may therefore serve as an additional marker of microbial exposure. OBJECTIVE: To study the factors determining the level of indoor exposure to muramic acid/peptidoglycan, as well as its potential association with respiratory health. METHODS: In 553 farm and nonfarm school children from Austria, Switzerland, and Germany, mattress dust muramic acid concentrations were determined, and health was assessed by using IgE measurements and questionnaire information. RESULTS: The muramic acid concentration was found to be significantly higher in dust from farm children's mattresses than in dust from nonfarm children's mattresses (157 vs 131 ng/mg). Children with higher mattress dust muramic acid concentrations had a significantly lower prevalence of wheezing (odds ratio of highest vs lowest tertile of muramic acid concentration, 0.3; 95% CI, 0.1-0.9), regardless of farming status and endotoxin exposure. The association for asthma was similar, and no association was found with atopic sensitization. CONCLUSION: Next to endotoxin, muramic acid provides us with an independent marker of microbial exposure. Unlike endotoxin, muramic acid was inversely associated with wheezing rather than with atopic sensitization.     

Properties of voltage-gated currents of microglia developed using macrophage colony-stimulating factor

Microglia were isolated from a murine neonatal brain cell culture in which their development had been stimulated by supplementation with the macrophage/microglial growth factor macrophage colony-stimulating factor (M-CSF). Using the whole-cell configuration of the patch-clamp technique, voltage-gated membrane currents were recorded from these microglial cells. Hyperpolarization induced inward rectifying K⁺ currents, as described for microglia from untreated cultures. These currents activated negative to the K⁺ equilibrium potential and, with a strong hyperpolarization, displayed time-dependent inactivation. The inactivation was abolished when extracellular NaCl was replaced by N-methyl-d-glucamine (NMG), thereby indicating a partial block of this K⁺ conductance by Na⁺. Inward rectifying currents were also blocked by extracellularly applied Cs⁺ or Ba²⁺. They were slightly diminished following treatment with extracellular tetraethylammonium chloride (TEA) but were not affected by 4-aminopyridine (4-AP). Upon long lasting depolarizing voltage pulses to potentials positive to 0 mV, the cells exhibited a slowly activating H⁺ current which could be reduced by application of inorganic polyvalent cations (Ba²⁺, Cd²⁺, Co²⁺, La³⁺, Ni²⁺, Zn²⁺) as well as by 4-AP or TEA. Based on their kinetics and pharmacological characteristics, both currents detected on M-CSF-grown microglia are suggested to correspond to the inward rectifier and the H⁺ current of macrophages.